From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [Bugme-new] [Bug 38102] New: BUG kmalloc-2048: Poison
 overwritten
Date: Mon, 04 Jul 2011 16:53:52 +0200
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References: <bug-38102-10286@https.bugzilla.kernel.org/>
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Cc: Alexey Zaytsev <alexey.zaytsev@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	netdev@vger.kernel.org, Gary Zambrano <zambrano@broadcom.com>,
	bugme-daemon@bugzilla.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Pekka Pietikainen <pp@ee.oulu.fi>,
	Florian Schirmer <jolt@tuxbox.org>,
	Felix Fietkau <nbd@openwrt.org>, Michael Buesch <mb@bu3sch.de>
To: Michael =?ISO-8859-1?Q?B=FCsch?= <m@bues.ch>
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Le lundi 04 juillet 2011 =C3=A0 16:43 +0200, Michael B=C3=BCsch a =C3=A9=
crit :
> On Mon, 4 Jul 2011 16:27:26 +0200
> Michael B=C3=BCsch <m@bues.ch> wrote:
> > We do this in b43, which has exactly the same DMA engine.
>=20
> (Ok, it turns out we don't do this in b43 (We only do it on the TX si=
de).
>  But that's a bug. We should do a wmb() on the RX side before advanci=
ng the
>  descriptor ring pointer.)


Also it appears rx_ring (or tx_ring ) are not necessarily 4K aligned if
kzalloc() path is taken.

(SL?B DEBUG -> kzalloc(4096) might not be 4K aligned)